Effect of Methionine and Threonine on the Hypercholesterolemia Induced by Polychlorinated Biphenyls in Rats Fed a Nonprotein Diet

Abstract

It was previously reported that the hypercholesterolemia induced by polychlorinated biphenyls (PCB) was influenced by dietary protein quantity and quality. On the other hand, the supplementation of methionine and threonine to a nonprotein diet ameliorated the body weight loss and decreased the urinary urea excretion in rats. We examined the effect of methionine and threonine supplements on the hypercholester olemia induced by PCB in rats fed a nonprotein diet. The administration of PCB increased plasma cholesterol concentration and the supplements of methionine and threonine to the nonprotein diet significantly accel erated the elevation of plasma level of cholesterol due to PCB feeding. Liver microsomal 3-hydroxy-3-methylglutaryl coenzyme A reductase ac tivity in rats fed the nonprotein diet was also elevated by PCB administra tion and the supplementation of methionine and threonine caused further inducing effect.